Hydrocarbon fuelled gas turbines have two drawbacks. Firstly, they are inefficient and secondly, they produce an unacceptable level of noxious emissions. Hydrogen fuelled gas turbines are replacing hydrocarbon fuelled gas turbines, in order to reduce noxious emissions. However, the replacing of hydrocarbon fuelled gas turbines with hydrogen fuelled gas turbines does not address the issue of the overall efficiency of the gas turbine. A continuous stream of heat and water vapour is exhausted from hydrogen fuelled gas turbines, together with nitrogen oxide emissions. The nitrogen oxide emissions are a byproduct of the air used as a source of oxygen for combustion.